Concrete Field Testing Technician Study Guide

Transcription

1 Concrete Field Testing Technician Study Guide ASTM C 172 SAMPLING FRESH CONCRETE 1. The maximum allowable time between obtaining the first and final portions of a composite sample is minutes. (Section 4.1) 2. The sample shall be when the concrete contains aggregate larger than that appropriate for the molds or equipment. (Section 6.1) 3. When wet sieving, mortar adhering to the sides of the sieves shall be scraped back into the batch used for testing. True or False (Section 6.4.1) 4. After wet sieving, the composite sample must be with a shovel to ensure uniformity prior to testing. (Section 6.4.1) 5. After all concrete samples have been transported to the place where tests are to be performed; the samples must be and with a to ensure uniformity. (Section 4.1.1) 6. Tests for temperature, slump, and air content, shall be started within minutes after obtaining the final portion of the composite sample. (Section 4.1.2) 7. The molding of strength specimens shall begin within minutes after fabricating the composite sample. (Section 4.1.2) 8. After obtaining the concrete sample, it must be protected from,, and other sources of and from. (Section 4.1.2) 9. The size of a sample to be used for strength testing should be a minimum of ft 3. (Section 5.1) 10. When sampling from a stationary mixer, collect or more portions taken at spaced intervals from the portion of the batch. Combine portions into one sample before testing. (Section 5.2.1) 11. Concrete samples from a truck mixer must be obtained before any water or admixtures are added to the mixer at the job site. True or False (Section 5.2.3) 12. Collection of a sample of concrete from a revolving drum truck mixer includes obtaining at least portions taken at regularly spaced during discharge of the middle portion of the batch. (Section 5.2.3) 2019 Page 1

2 13. Two methods for obtaining a sample of concrete from a revolving drum mixer are to repeatedly pass a receptacle through the entire stream or to completely the discharge stream into a sample container. (Section 5.2.3) 14. If needed, the rate of discharge may be regulated by adjusting the rate of of the. (Section 5.2.3) 15. When sampling from a continuous mixer, concrete samples should not be obtained until all have been made and only after cubic feet or more of concrete has been discharged. (Section 5.2.4) 16. After combining sample portions from a continuous mixer into a composite sample, wait a minimum of minutes and a maximum of minutes before beginning tests. (Section 5.2.4) 17. When sampling from a paving mixer, the contents of the paving mixer and obtain samples from at least different portions of the pile. (Section 5.2.2) 18. Samples from open top truck mixers should be obtained by the most applicable method which will produce a representative sample. True or False (Section 5.2.5) ASTM C 1064 TEMPERATURE 19. ASTM C 1064 may be used to verify with specifications. (Section 4.1) 20. Concrete containing aggregate with a nominal maximum aggregate size greater than 3 inches may require up to minutes before the temperature stabilizes after mixing. (Section 4.2) 21. The temperature measuring device shall be capable of measuring the temperature of fresh concrete to ± F and throughout the range of F to F. (Section 5.2) 22. The temperature measuring device shall be verified, or whenever there is a question of. (Section 6.1) 23. Reference thermometers must be accurate and readable to ± F. (Section 5.4) 2019 Page 2

3 24. The accuracy of TMD s must be verified at temperatures at least apart. (Section 6.1) 25. The temperature of fresh concrete may be measured in the transporting equipment or forms providing there is at least 3 of cover. True or False (Section 7.1) 26. If transport equipment or forms are not used as the container, prior to sampling, you must the sample container used for obtaining the temperature of fresh concrete. (Section 7.2.1) 27. A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True or False (Section 7.2.2) 28. The thermometer sensor should be immersed a minimum of inches into the concrete and have at least inches of concrete cover in all directions. (Section 7.1 and Section 8.1) 29. After inserting the thermometer, the concrete must be pressed around the temperature measuring device to prevent the temperature from affecting the reading. (Section 8.1) 30. Leave the temperature measuring device in the concrete for at least minutes, but not more than minutes before reading. (Section 8.2) 31. The temperature measuring device may be removed from the concrete for reading. True or False (Section 8.2) 32. After reading, record the temperature to the nearest F. (Section 8.2) ASTM C 143 SLUMP OF HYDRAULIC CEMENT CONCRETE 33. The slump test is applicable to concretes with a maximum aggregate size of inches. If the concrete contains aggregate larger than inches, wet sieve over the inch sieve. (Section 4.2) 34. The rigid surface or base must be large enough to contain all of the slumped concrete. True or False (Section 5.1 and Section 7.1) 35. The tamping rod used in the slump test is a smooth steel rod of inches in diameter and has at least one tip. (Section 5.2) 36. The height of the slump cone is inches with a base opening of inches and a top opening of inches. (Section 5.1) 2019 Page 3

4 37. Slump molds should be verified before first use and at least thereafter. (Section 5.1.1) 38. Slump molds may be made of metal or plastic. True or False (Section 5.1) 39. The measuring device used to determine slump must have inch divisions or smaller. (Section 5.3) 40. Before filling, the mold and. Place the slump cone on a rigid,, level, non absorbent, surface free of. (Section 7.1) 41. The slump mold is filled in three layers of equal. (Section 7.1) 42. Rod each layer times using the end of the tamping rod. (Section 7.2) 43. During rodding, the rod must be to allow consolidation of the concrete near the perimeter of the mold. (Section7.2) 44. When rodding a second or third layer, the rod must penetrate approximately inch into the previous layer. (Section 7.2) 45. If the concrete drops below the top of the slump mold during rodding of the final layer, rodding must be discontinued until concrete has been added to raise the level above the rim, then resumed until 25 roddings have been completed. (Section 7.3) 46. The should be used to strike off the top surface of the concrete using a rolling and motion. (Section 7.3) 47. After strike off, the concrete from around the base of the mold to prevent interference with the slumping of the concrete. (Section 7.3) 48. Raise the mold vertically without lateral or torsional movement, a distance of inches, in + seconds. (Section 7.3) 49. Complete the slump test from filling to removal of mold in a time of minutes. (Section 7.3) 50. Determine the slump by measuring the vertical distance between the top of the mold and the original center of the concrete surface. (Section 7.4) 2019 Page 4

5 51. If a decided shearing away occurs, the test and make a new test on another portion of the sample. (Section 7.4) 52. Report slump to the nearest inch. (Section 8.1) ASTM C 31 MAKING AND CURING CONCRETE TEST SPECIMENS 53. The concrete used to make the molded specimens shall be sampled after all on site have been made to the mixture proportions. (Section 1.2) 54. When strength specimens are to be made,,, and tests must also be conducted. (Sections 8.1, 8.2, and 8.3) 55. For a 6 x 12 cylinder, the tamping rod must be a round, straight steel rod with a diameter of inches, but if using a 4 x 8 inch mold, the inch diameter rod must be used. (Table 1) 56. The minimum frequency of an internal vibrator used in this procedure is vibrations per minute. The diameter of the vibrator should be no more than the diameter of the cylinder mold or width of the beam mold. (Section 5.5) 57. The required weight of mallet used in this procedure is lbs. (Section 5.6) 58. When placing concrete in a beam mold, either a scoop or shovel is permitted. True or False (Section 5.7) 59. For acceptance testing for specified compressive strength, cylinders shall be x in. or x in. (Section 6.1) 60. For a cylinder, if the nominal maximum aggregate size of the coarse aggregate exceeds inches, the concrete must be over the 2 inch sieve prior to placement in the mold. (Section 6.1) 61. Consolidation of concrete having a slump of less than one inch must be accomplished by using when making cylinders or beams. (Table 3) 62. When molding 6 x 12 cylinders by rodding, the concrete is placed into the cylinders in equal layers and each layer is rodded times. (Table 4) 63. When using an internal vibrator to consolidate a 6 x 12 compressive strength test specimen, the mold is filled in layers and the vibrator must be inserted at different points for each layer. (Table 5) 2019 Page 5

6 64. When rodding the upper layer(s) of a cylinder, the tamping rod should penetrate the underlying layer by about inch. (Section 9.4.1) 65. When molding 4 x 8 cylinders by rodding or vibration, the concrete is placed into the cylinders in equal layers. (Table 4 and Table 5) 66. For cylinder molds which may be dented or permanently distorted by using a mallet; after consolidation of each layer you must tap the outside of the mold 10 to 15 times using an. (Section 9.4.1) 67. Underfilled molds shall be adjusted with representative concrete during of the top layer. (Section 9.4.1) 68. Strike off the concrete surface of cylinders using the or a handheld or trowel to produce an even surface that has no depressions or projections larger than inch. (Sections 9.5 and 9.5.1) 69. You may cap the top surface of freshly made cylinders with a thin layer of Portland cement paste which is then permitted to harden and cure with the specimen. True or False (Section 9.5.1) 70. After strike off, verify that the mold has been to identify the concrete it represents. (Section 9.6) 71. After strike off, provide protection to prevent loss, and move the specimen to an place for storage. (Sections and ) 72. The standard size beam is inches wide by inches deep and a minimum of inches long. (Section 6.2 and Section 6.2.1) 73. For beams, if the NMAS is greater than 2 inches, wet sieving over the 2 inch sieve is required. True or False (Section 6.2.2) 74. A standard sized beam is filled in lift(s) when rodding and lift(s) when using a vibrator. (Table 4 and Table 5) 75. The number of roddings required per layer for a flexural strength specimen is one rodding for each square inches of the top surface area of the beam. (Section 9.3) 76. After rodding and tapping each layer of a beam specimen, you must spade along the sides and ends with a trowel or other suitable device. True or False (Section 9.4.1) 2019 Page 6

7 77. When internal vibration is used to consolidate a standard flexural strength test specimen, the vibrator is inserted at intervals not exceeding along the centerline of the beam. (Section ) 78. When using a vibrator to consolidate a beam, you must tap the outside of the mold after vibration at least times with a. (Section ) 79. The supporting surface on which specimens are stored shall be level within per. (Section ) 80. Standard Curing is the method used when test specimens are to be used for testing, checking the of mixture proportions, and. (Section 4.2 Section 4.2.3) 81. Field Curing is the test method used when test specimens are to be used for determining when a may be put into use, comparison testing, the adequacy of and of the concrete in the structure, and removal time requirements. (Section 4.3 Section 4.3.4) 82. When Standard Curing concrete mixtures with a specified strength of less than 6000 psi, initial curing requires that the specimens be stored for a period up to hours in a temperature range from F to F. (Section ) 83. Concrete mixtures with specified strengths of 6000 psi or greater shall have an initial curing temperature between F and F. (Section ) 84. Specimens shall not be transported until at least hours after final set and the transportation time shall not exceed hours. (Section 11.1) 85. During transportation, test specimens must be protected from damage due to,, and. (Section 11.1) 86. Upon completion of initial curing, the test specimens may be left in their molds and sealed in plastic bags. True or False (Section ) 87. Upon completion of initial curing and within minutes of removing the mold, cure specimens by maintaining free on all surfaces at a temperature of ± F. (Section ) 88. Beams must be cured by storing in water saturated with at 73.5 ± 3.5 F at least hours prior to testing. (Section ) 89. Beam surfaces are allowed to dry prior to testing. True or False (Section ) 2019 Page 7

8 90. When field curing cylinders, provide like and conditions as the structural work. (Section ) 91. When reporting data for strength test specimens, it is important to report the location of placement, time of casting, and the curing method. True or False (Section 12) ASTM C 138 DENSITY (Unit Weight) 92. The balance used during the density test must be accurate to lb or to within % of the test load, whichever is greater. (Section 4.1) 93. The measure must be made of metal when determining the density of fresh concrete. True or False (Section 4.4) 94. The size of the measure required is based on the size of the aggregate. Therefore, there is no wet sieving required by this method. (Section 4.4) 95. Determine the volume of the measure using ASTM yearly and report the volume of the measure to the nearest ft³. (Section 4.4 and Section 8.1.3) 96. The tamping rod length must be at least inches greater than the depth of the mold being used but not greater than inches. (Section 4.2) 97. The required frequency of the vibrator used in this test method is at least vibrations per minute. (Section 4.3) 98. A metal strike off plate must be at least inch thick and if made of glass or acrylic at least inch thick. The length and width of a strike off plate must be at least inches greater than the diameter of the measure. (Section 4.5) 99. The specified weight of the mallet used on measures that are 0.5 ft 3 or smaller is + lbs. (Section 4.6) 100. must be used to consolidate concretes with a slump less than 1 inch, whereas must be used to consolidate concretes with slumps greater than 3 inches. (Section 6.1) 101. If rodding is the method of consolidation, the measure must be filled in layers of approximately equal volume. (Section 6.3) 102. For a measure of 0.5 ft 3 or smaller, strokes of the tamping rod are required for consolidation of each layer. (Section 6.3) 2019 Page 8

9 103. After rodding each layer, tap the sides of the measure using the mallet to times to close the voids left by the tamping rod. (Section 6.3) 104. If vibration is the method of consolidation, the measure must be filled in approximately equal layers. (Section 6.4) 105. When using an internal vibrator, the vibrator is not allowed to touch the sides or bottom of the measure. True or False (Section 6.4) 106. Prior to filling the measure, the measure must be and then. (Section 6.2) 107. After filling and consolidation of the final layer, an excess of inch of concrete above the rim of the mold is considered ideal. (Section 6.5) 108. Adjustments to the level of concrete is permitted after consolidation but must be made prior to. (Section 6.5) 109. Strike off of the concrete surface must be made using the strike off, with the final stokes accomplished by the plate to produce a smooth surface. (Section 6.6) 110. After strike off, all excess concrete must be removed from the exterior of the bowl before weighing. True or False (Section 6.7) 111. Report the density of concrete to the nearest lb/ft³. (Sections 8.1.4) 112. Yield is defined as the of concrete produced from a known quantity of materials. (Section 1.1) 2019 Page 9

10 ASTM C 231 AIR CONTENT BY THE PRESSURE METHOD 113. Air content by the pressure method determines the air content from an observation of the change in of concrete with a change in. (Section 1.1) 114. This test method is intended for use with concretes that contain relatively aggregates for which an aggregate correction factor can be determined. (Section 1.2) 115. Air content by the pressure method is not appropriate for concretes made with aggregates, air cooled blast furnace slag, or aggregates of high. (Section 1.2) 116. The minimum capacity of the measuring bowl used in this test is cubic feet with a typical volume of the type B meter bowl being cubic feet. (Section 4.2 & Slideshow) 117. If a vibrator is used for consolidation it must conform to ASTM and have a frequency of at least 9000 vibrations per minute. (Section 4.15) 118. The strike off bar which may be used is a flat, metal bar at least inch thick, inches wide, and inches long. (Section 4.11) 119. A check of the air pressure gauge dial readings is required every months. (Section 5.1) 120. An aggregate correction factor is required by this method. True or False (Section 6.1) 121. If the concrete to be tested contains aggregate retained on the inch sieve, the sample must be wet sieved over the inch sieve prior to testing. (Section 7.1) 122. Consolidate concrete in this method by: concrete with a slump of greater than 3 inches; or concrete with a slump of 1 to 3 inches; concrete with a slump of less than 1 inch. (Section 8.1.1) 123. Prior to filling the mold with concrete, the mold must be. (Section 8.1.1) 124. When consolidation is accomplished by rodding, place the concrete in the bowl in equal layers and rod each layer times. After rodding, tap the sides of the bowl with a mallet to times. (Section 8.1.2) 2019 Page 10

11 125. If the concrete sample is to be consolidated by vibration, the measure is filled in layers of equal volume. Insert the vibrator times per layer. (Section 8.1.3) 126. Never continue vibration long enough to cause the escape of from the sample. Over vibration may cause and loss of intentionally entrained air. (Section and Note 6) 127. The strike off or the strike off may be used in this method to strike off the top surface of the concrete after consolidation. (Section 8.1.4) 128. the rim of the measuring bowl and cover assembly prior to attaching the cover assembly to the measuring bowl. (Section 8.3.1) 129. For a Type B meter, after clamping the cover to the bowl, is injected into one petcock using a syringe until it emerges from the opposite petcock. Continue filling with water and the meter, until all trapped air is expelled. (Section 8.3.1) 130. After filling a Type B meter with water, the air bleeder valve, and pump air into the chamber until the hand on the dial gauge is on the initial pressure line. The petcocks are during this operation. (Section 8.3.2) 131. After stabilizing the pressure on the initial pressure line, both petcocks and the main air valve while striking the sides of the measure with the to remove trapped air. (Section 8.3.2) 132. While holding the main air valve open, lightly the gauge with your hand and read the dial when stable. Then release the main air valve. (Section 8.3.2) 133. Release the pressure in the measure by both petcocks. Remove cover before releasing the air in the air chamber. (Section 8.3.2) 134. If water enters the air chamber, it must be from the chamber and blown out using the pump to prevent errors in the next measurement. (Section 8.3.2) 135. The aggregate correction factor is from the dial reading to determine the final air content. (Section 9.1) 136. Report the % air to the nearest % if the reading is from 0 8 %, and to the nearest division if it exceeds 8 %. (Section ) 2019 Page 11

12 ASTM C 173 AIR CONTENT BY THE VOLUMETRIC METHOD 137. Air content by the volumetric method can be performed on concrete containing any type of aggregate. True or False (Section 1.1) 138. The bowl volume must be at least ft³. (Section 4.1.2) 139. The tamping rod for the volumetric air meter shall have a diameter of inches and be at least inches longer than the depth of the bowl, but not more than inches in length. (Section 4.3) 140. The strike off bar made of steel shall have dimensions of at least x x inches, and if made of plastic the require thickness increases to inch. (Section 4.4) 141. The rubber or rawhide mallet required for this test should have a mass of approximately lbs. (Section 4.11) 142. The calibrated cup is used only to add when the air content exceeds 9 % and should be equal to ± % of the bowl volume. (Section 4.5) 143. The alcohol used in this test method must be with a concentration of % by volume. (Section 4.10) 144. Calibrate the meter and calibrated cup initially and thereafter. (Section 5.1) 145. If the concrete for testing by the volumetric method contains aggregates that would be retained on an inch sieve, wet sieve a sufficient amount of the sample over a inch sieve. (Section 6.1) 146. Prior to filling the bowl, the inside of the bowl and remove any water from the bottom. (Section 7.1) 147. The bowl of the meter will be filled with fresh concrete in layers of approximately equal volume. (Section 7.1) 148. Rod each layer times with the tamping rod. (Section 7.1) 149. After each rodding, tap the sides of the bowl to times with a mallet to close any voids left by the tamping rod. (Section 7.1) 150. Adjustment to the concrete level may be made after strike off. True or False (Section 7.1) 2019 Page 12

13 151. Prior to attaching the top section, the top section including the gasket. (Section 7.3) 152. After attaching the top section, insert the and add at least pint of water followed by the selected amount of alcohol. Then, continue to add water through the funnel until the water level is seen in the. Remove the funnel and fill the neck with water until the bottom of the is level with the zero mark. (Section 7.3) 153. After securing the lid, invert the meter and shake to free the concrete from the. Do not keep the meter inverted for more than seconds at a time to prevent lodging of aggregate in the neck. (Section 7.4.1) 154. Repeat the inversion and shaking procedure for a minimum of seconds. (Section 7.4.1) 155. After freeing the concrete from the base, roll the meter for approximately minute. (Section 7.4.2) 156. After rolling, set the meter upright and allow the liquid level to stabilize. The liquid is considered stable when it does not change by more than % in a minute time period. (Section ) 157. When the liquid level is stable without excessive foam, read the bottom of the meniscus to the nearest %. This is recorded as the meter reading. (Section ) 158. If there is more than % foam after the initial rolling procedure, discard the test and start a new test using more. (Section ) 159. During this test, the meter must be rolled at least but no more than times. (Section 7.4 Section 7.5) 160. For this test to be completed, the maximum amount of change between the recorded initial and final meter readings is %. (Section ) 161. If there are portions of undisturbed, tightly packed concrete found in the bowl when emptying, the test is valid. True or False (Section 7.6) 162. If more than pints of alcohol are used, a correction to the final meter reading is required. (Section 8.1) 163. The final air content is reported to the nearest %. (Section 8.2.1) 2019 Page 13